Selective Breeding

                                    Select Aquatics / Greg Sage

                                           Revised 2023


                   Originally published in “Livebearers”, Journal of the American Livebearers Association . First published in 2003,
                   it was revised in 2011, where it appeared in various publications, and was updated in September 2023 for
                   use by The Darter / Missouri Aquarium Society


                   I had kept community tanks for over 40 years, and decided around 1995 to devote a few tanks to working with just
                   one line of livebearers, hoping to develop something I thought looked good, representing better quality, consistent
                  color, size and finnage than what I had. I knew I didn’t have the knowledge of genetics I thought I’d need to
                  introduce specific physical characteristics, but with all I had read about careful record keeping and observing fish
                  closely, I thought I’d be able to “stabilize” a line toward its best looking individuals. I believed that it shouldn’t be
                  too difficult to get a line to look fairly consistent, close to how I thought it should look, producing desired,
                  attractive and healthy fish.

                  Select Aquatics has always focused on rare livebearers that were both disappearing from the wild and from the hobby,
                  There are selectively bred morphs of the Characodon lateralis, audax and other species that are not common
                  in the hobby coming out of Europe, but I did not want to genetically fuss with any of those species, where the selectively
                  bred versions could come to represent that species in the hobby.

                 Also, guppy breeders established long ago that new traits do not become established for at least 11 generations. So, as
                 has been documented with domestic lines of pet store platys released to bodies of water in Florida, genetically manipulated
                 fish will return to their wild coloration within 3-4 generations. Also, the effects of domestic breeding manipulation will diffuse
                 quickly when breeding with wild, normally colored fish.

                 The journey to selectively breed my own lines of fish proved to be exciting and humbling. I found that I knew less than I
                 thought, but could accomplish what I wanted to accomplish by keeping at it, and using common sense to keep track of my best
                 breeding individuals, maintaning the line at its best health, and carefully raising up every fry.

                 In the mid- 1990s I started this process with a well planted 100 gallon show tank filtered with a well aged wet/dry trickle
                 filter, a mature fluidized bed filter on the back and over 30 years experience at keeping fish. In this large tank
                 I kept trays of peat beneath a ½” layer of natural pea gravel that supported large trunks of carefully trimmed
                 Watersprite (Ceratopteris- they looked liked a maintained Bonsai forest) and Vallisneria, and I had moved out all of
                 the fish. My goal was to have these beautiful surroundings with the big IFGA (International Fancy Guppy association)
                 delta tailed guppies swimming between the plants. I was willing to set up a couple 20 gallon tanks for babies and for
                 quarantine. So those guppies were my first choice, yet I knew nothing about these fish, other than that they were

                 In fewer words, I had absolutely no idea what I was doing.

                How hard can guppies be to keep? I hadn’t talked to anyone, or read a thing about them, thinking I knew guppies.
                For the majority of my time keeping tanks I’ve always had a line or two, and I’d kept guppies pretty heavily when I
                was in high school. I came to find out that everything I needed to know about keeping and breeding any other fish in the
                hobby would be learned by keeping these high quality guppies, and the issues I encountered.

                I set out to buy the best IFGA Guppy stock I could find. Through the classified ads in the back of fish
                magazines, I contacted a couple breeders and even set up appointments to tour their fishrooms. One room
                involved a 7 hour drive to L.A. from where I was living, but it was entirely worth the effort. I explained what I
                wanted to do, and that I was willing to spend a little money to start with a few quality fish.

                The fishroom in L.A. was mindblowing. This guy had close to 200 tanks, and most of them were 30, 50 and 90 gallon
                tanks. All stocked heavily with thousands of guppies. Entire rows with tanks on both sides, all filled with bright
                delta tails- dozens of tanks that in many cases were full of the same line of identical fish! With a great eye and
                years of experience he scanned the fish as they matured, looking for tiny advantages or flaws in any particular fish,
                carefully picking his next line of breeders.

                I did my best to pick every corner of his brain I could get into. “How extensive is your record keeping?”
                I asked. “ He responded "I don’t keep records. In fact I really don’t write anything down.” He had dozens of lines.
                Thousands of fish. 200 aquariums, and he doesn’t keep any records. I was then warned that my planted 100 gallon tank
                idea was not a good one, but I didn’t understand why. Today I realize that those breeders probably figured
                there wasn’t enough time in the day to explain what I needed to know.


                Starting off learning to selectively breed and develop a line of fish with fragile, high end guppies was the best thing
                I could have done. Every issue I could have had with a selective breeding program, and maintaining overly sensitive
                fish was waiting for me. The lessons were priceless. You quickly learn to establish control over each variable in your
                fishkeeping and selective breeding process, and to carefully watch your fish to better understand their care, and what
                is best for them (and not just you), and how they are responding to the developments you are introducing them to.

                I bought 3 trios and ran into problems before the fish had even arrived. To prepare for their arrival, I was told to totally
                clean everything with bleach. Tanks, filters, nets, siphon hoses, tubing, everything. All of the established biofiltration had to
                be started from scratch, and for evermore any fish from outside of my fishroom had to stay outside of my fishroom. No more live
                plants or gravel. These top quality fish, at close to $100 a trio back in 1995, were coming from what I was assured were
                totally disease free environments, and must be introduced to a similar setup. The breeders I visited even kept these cute
                little dipping buckets filled with a weak chlorine bath for dipping their nets, to prevent any spread of bacteria between tanks.
                Salt was maintained in the water at 1 tblsp. per five gallons of water. Everything had to be kept clean, clean, clean.
               With the salt in the water and careful, nearly obsessive observation of the fish, I began to understand why I didn’t see plants
                or gravel in any of the tanks of the champion breeders I visited. I maintained those guppies for 5 years.

                I don't do most of that today. However, my basic set up in all of the tanks here in 2023 are influenced from those early practices,
                and what I learned about the dangers of allowing mulm and debris to build up, and where bacteria could fester in a way that could
                bring down your water quality, causing disease, lack of breeding and problems with your fish.

                Gravel harbors organic waste that can contribute to fungal and bacterial infections, and limits your control over the
                cleanliness of the overall tank environment. For consistent health of your fish, it is best to assume that mulm and debris are
                never inert, and must always be kept to a minimum.

                With hardier species, such as those in the commercial pet trade, all of these precautions may not be required to keep them alive.
                But to raise your fish to their best size, color, and to be as disease resistant as possible, I needed to maintain those practices. A
                large part of selective breeding is raising every fry, as mutations are not uncommon, and losing individuals due to poor water
                quality can limit your selective breeding program.

                Multiple bare-bottomed single species tanks would be easier to maintain, though they might not be much to look at, and
                how the tanks look was certainly important to me. The tanks were now bare, clean and functional, with a visual focus on the fish.
                So I eventually introduced plants to provide hiding places for fry, and to address the need for security in some fish.
                A more natural environment encourages breeding and healthy spawns. Today I maintain heavily planted
                tanks for display and grow out, but with selectively bred individuals where losing any is not an option, the tanks are simply
                a single pebble layer of gravel over 1/3 to 1/2 of the tank bottom, providing essential nitrifying bacteria area, some floating plants,
                filtration, low light and heat (when necessary), and the fish.

                The mechanical and biological filters are no longer the primary means of filtration. The filters maintain the
                biological health of the water, and with the in-tank livebearer-style box filters, excess mulm and debris can pretty much be kept
                in check. The main source of filtration would be water changes, and keeping an appropriate number of fish fed so that
                decaying food does not affect water quality. Today, all of my young grow out tanks receive 10% - 15% daily water changes,
                and the majority of the rest of the room receives 2 - 3 water changes per week amounting to roughly 60%.

                An ultraviolet sterilizer is not a bad idea, but does begin to get in the way of keeping things simple and inexpensive. If you are
                selective breeding to eventually build out fish for sale, keep in mind that too much extra care could produce fish that when tossed
                into a standard, minimally maintained community tank, they may not adapt. It is not always enough to provide fish that are healthy when
                they leave your facility- it is your responsibility that they are hardy enough to withstand broad changes in water conditions and
                husbandry when introduced to their new environment.

                No fish can handle abuse for very long, and you want to be sure that you do not provide extra care that the customer will not.
                Fish raised with a UV sterilizer, 10% daily water changes, prophylactic doses of salt with water changes, and possibly regular
                dosing of a disease preventative are done routinely by some aquarists. However, someone taking a fish from that level of care
                and putting them into an established tank with other species, without the sterilizer, salt, preventative medications, at slightly
                different temps, diet and feeding, the new fish may not do well.

                It should be assumed that all customers purchasing your fish will put them into a quarantine tank by themselves at first.
                A quarantine tank is often more about introducing the arrival to new water qualities, husbandry and foods, and achieving best health
                for them, before meeting new tank mates and adjusting to their their eventual destination.


               So in that first Guppy breeding program I have a couple of bare bottomed tanks, with the outside of the bottom glass plate
               painted black to bring out the colors of the fish, no plants, a 100 gallon tank empty except for the clear water cycling through
               brand-new filters, and a couple trios of very young, tiny, and what for me were incredibly expensive fish.

               The books I read said livebearers would require 4 tanks per strain; a male grow-out tank, a female grow-out tank, a baby raising
               tank and a mating/breeding tank. That's great until you have more than one gravid female at a time. If you breed your line
               in trios, as you should, tank space issues will present themselves fairly quickly.

               With barbs, danios, and similar egg scatterers you also need a minimum of 4 tanks- a male adults
               tank, a female adults tank (where the females can also be conditioned separately for spawning), a breeding/ new fry tank
               and a fry grow out tank. Most cichlids will require more tanks, because they are generally larger, can be territorial,
               and don’t breed in groups. Cichlids (where spawns can be 200+ fry) require a fry grow-out tank, grow-out tanks for
               young from about a month old until they pair off, and a separate tank for each mated pair to spawn in. This
               means that all tanks will be species-only tanks.

              I do maintain a “cull tank” that looks great with fish that show off a little of what I am doing in the room, but they are primarily
              tanks set up so that I have backup fish to use as breeders if needed.

              I recommend keeping a collection of portable, lightweight containers on hand to serve as temporary “housing” as fish
              are born and numbers take off. I use the 10 or 12 gallon sized, white plastic kitchen-type trash containers, and only
              use those made by Sterilite, with a few plants and a box filter. This isn’t a plug for Sterilite- some companies use softeners
              in their plastic that can be toxic to fish. I have found this to be the case in the past with Rubbermaid products, and lost many
              fish until I discovered what the problem was.

              The biggest drawback to using those white trash cans in a breeding program is that the bright white sides wash out
              the color in the fish when reasonably well lit- and the color quickly returns when put back into a normal environment.
              The biggest drawback is that you are not able to observe them, which keeps their use to a temporary basis. For the extra
              female about to pop, they are perfect with a little Java moss to protect any fry.

              Raising up the sexes up separately is essential with many species. With guppies, males develop a gonopodium by their first
              month. From then on their energy and time is spent chasing and courting females or competing with one another, when you
              want them eating and building finnage. Separating them puts their energy into growth, and the differences in size when the
              sexes have been grown out separately is substantial. The trick then becomes at what point are as good as they were going
              to get, but not too old to breed? That is something I’ve simply I had to learn as I’ve been doing this. When raised separately,
              they get much larger, and when choosing breeders you can then see each fish at closest to its potential.

              There is a basic rule when breeding and selling fish that was told to me many years ago. It is a tough rule to stick to,
              but is essential to any serious breeding program. And that is that if you can't breed it, and you can't sell it, you have to get it
              out of your fish room.

              Successful selective breeding means culling, which I do understand the need for. But intentionally killing fish wasn’t
              something I wanted to do. Previously, when fish die it had always been a bad thing. I once heard a comic say that he liked to
              watch things die… so he bought a fish tank. I was pleased to see, however, that even some of the most macho breeders that
              shrug over killing hundreds of fish often have a pond in their back yard full of their culls, local petshops full of their culls, friends’
              tanks full of their culls…

              Selling or marketing your culls is not always an option. Until the traits you are working to established are “fixed”, in that the
              majority of the fish you produce carry the trait, you do not want to release poorly, inconsistently finned, poorly colored or
              “half-assed” versions of your final product out to your eventual customers. When you are finally able to sell the finished product,
              you may find that there is no longer a market, because fishkeepers already have tanks of inferior versions of the line you have
              worked so hard on. And worse, they got them from you!


              Your First Fish

             When you buy fish from someone else to start a breeding program, the fish are coming from foreign water, husbandry, food etc.
             The goal from your first fish is to receive young born in your water. With most fish, especially the livebearers, my experience has
             been that those initial purchased individuals generally don’t live a full lifespan. Their young should grow out well, and my experience
             has been that getting fish into your tanks of the size and color of those you saw at the website, or at the breeder’s fishroom, won't
             appear until the second or third generation beyond the original stock.

             So with guppies, for example, at 4 months per generation, assuming the fish you receive drop within a month after you received
             them, it will be another 8 months before you are working with fish that display closer to the line’s potential. The best way to extend
             the life of the fish you buy is to purchase young fish and raise them up yourself. At the Select Aquatics, when obtaining a new
             species, I have found that fish growing to their full-color and size does not begin until into their third-generation.

             This is why someone cannot purchase fry from a line of show winning fish, then simply raise them up to win the same awards.
             Any breeder will need to work with that line for at least two generations before fish that come close to the quality of the original fish
             can be produced.

             I have also found that even with fish being kept in essentially empty tanks beyond the water, fish, filter and possibly a heater, do
             best when they are moved as little as possible. Consistent breeders need to be allowed to stay where they are, even though the
             water is the same throughout the room. The single biggest circumstance where I lose fish is when I must remove a female and put
             her in her own (generally smaller and more heavily planted) tank to drop fry. Though it may be cleaner, and without issues of her
             being harassed by the males, some species the fish may die shortly after being moved, or she’s living, but only after having dropped
             her young, all dead. A few species seem fairly prone to this, and with others it is not an issue. With species most prone to this, you
             can occasionally lose batches of young. (I have found that Ameca splendens is one species that can be this way). So if there is only a
             pair or trio in a tank by themselves, I may leave the female and remove the others, then put in a cloud of plants until
             she drops her fry.

             You will also find that tank placement can greatly affect how well a species will do, and whether it will reproduce for you.
             Over time at Select Aquatics, I kept notes as to where each species did best, and the differences could be substantial,
             though the water quality was the same. A combination of the temperature (some tanks placed higher were slightly warmer),
             amount of light the tank received (some fish preferred being closer to natural light coming in from a window), and the activity
             directly outside of the aquarium seem to be the variables most responsible.


            Harvesting Fry

            With species where the females are not removed to a tank of their own, I will keep them well fed, put a bunch of plants in
             for the babies to hide in, and then check the tank mid- late morning for fry until they appear, as most livebearers generally
             give birth between sun-up and noon. Then I’ll carefully remove whatever I can catch, or remove the female and grow out
             the fry in their birthing tank.

             In any breeding program, one of the strongest components of your effort is your ability to save every single fry, for you
             never know which fish will carry the traits you are looking for, or a new mutation appears that you will want to preserve.
             The “rule of thumb” was that of a drop of 30 young, you may get one pair worth keeping to consider as future breeders,
             the rest will need to be disposed of, somehow. Out of a strained logic to go natural, I started keeping something big
             and carnivorous in its own tank to eat the culls, such as an Oscar. All I ended up with was a fish that would go through
             periods of feast or famine, who took up a large tank and space I really needed for other things.

             I learned that the function of any particular tank can change often, and most problems can be solved by setting
             up another tank, which can cause your fishroom to expand pretty quickly. I recommend only keeping as many tanks
             as you can effectively provide maximum care for, cull to keep numbers down, and keep the number of strains you choose
             to work with to a minimum. Don't let your strains multiply each time you get a neat looking cull or two unless you are willing
             to increase the number of tanks as needed.

             And if females of two strains you are keeping near one another look alike, the potential for an accidental cross by a fish
             jumping between tanks is a real possibility- always separate tanks of fish that look too much alike, or that could cross.
             Creating greater numbers within a strain also increases your odds for the appearance of a mutation.

             The Easiest , Most Common Way to Screw Up

             The biggest mistake a breeder can make is to accidentally mix two similar looking species that may cross, or mixing two lines
             that must be kept separate. If a mix continues and goes into the next generation, the progress of any work on your line is stopped.
             However, mating two species that will cross - most will not - is not always an easy thing- a deliberate effort to cross two Xiphophorus
             species, for example, is not a case of simply putting two of the opposite sexes together. Having one or both species with
             others of their own species in the tank further discourages their breeding. Breeders trying to cross two fish that are not the
             same species will often set up many pairings, alternating the sexes, before a succesful fertilization. But with a mix of two lines
             of the same species- however different in appearance- their crossing is always a possibility.

             Contamination between tanks often occurs by fish jumping, or by being put there accidentally by you, or inadvertently
             riding along as a fry in a bunch of plants or between the folds of a net. With a consistent breeding program, contaminants
             getting into tanks needs to be kept to a minimum. I am careful not to keep tanks of closely related species near one another.

             Water Changes

             When establishing your water change routine, it took awhile for me to determine what amounts should be changed for
             the best effect for the fish. Though 35% a week is good, 5% a day is both far better but much more work. I eventually
             constructed an automatics Water change system (Youtube "Select Aquatics Presents - Building an Automatic Water
             Changing System and Keeping Rare Fish") Over time I have settled on about 10% per day for my grow out and line
             maintenance tanks, and the Pleco breeders have shown that they prefer less frequent, but more substantial changes,
             so they receive a 20-25% water change twice a week, and all tanks here are also on central sump filtration.
             (Youtube Select Aquatics Presents - Central Sumps and earning a Phd in PVC!)

             This water change system is entirely made of PVC that does not require any drilling of tanks, and is relatively portable.
             The PVC drain and fill tubing can be moved easily, and both the draining and filling happen on their own.

             Inbreeding and Appropriate Choice of Breeders

             As I meet other hobbyists, I’d ask for advice, and found that otherwise sensible, reasonable people will have strong
             opinions on an aspect of husbandry or the breeding process. Someone who believes in one approach can become
             thought of as a nutcase by someone else, so it became important to listen to everyone’s opinion, then figure out for
             yourself whether any of the information applied to you..

             To be honest, there may be no firm answers for many situations, and “the truth” may vary from one fishroom to another.
             What you feed, how often, your water qualities (pH, hardness, temperature and how often you do water changes),
             in combination with the characteristics of the species and line of fish you are working with can contradict rules that
             work well for someone else.

             The result is that there are theories that are often the result of once is an occurrence, twice is a coincidence, three times is
             a rule, and these commonly held beliefs may not hold up on closer inspection. One of these topics is inbreeding.

             Does it weaken or strengthen the line? When should you outcross, if ever? At the Xiphophorus stock center in San Marcos,
             Texas, Dr. Gordon collected wild lines in the 1930’s that have been inbred consistently for many dozens, and in some cases,
             more than a hundred closely bred generations, and they are doing well (with careful, extensive record keeping). So why do
             fish that are inbred often show bent spines and such after just one or two few generations?

              The reason may be non-intuitive, but can be easily understood. As you narrow the genetic diversity within a line of fish
              through close inbreeding of similar, consistent, related individuals, unwanted traits within the fish will gradually
              show themselves as they “rise to the surface”. In other words, as each aspect of the genetic diversity is
              expressed over time, over a large number of fish, undesired traits that are simply present within the genetic makeup of
              some individuals will present themselves as the line becomes more genetically homogenous.

              As the breeder you must cull those individuals, essentially removing those negative traits from the genetic makeup of the
              line, as you do with any fish that did not appear as you would like, toward “purifying” or stabilizing the look of the line you
              are working with. Bent spines are simply another trait that will appear over the first three generations in many species, when
              they are inbred, and those deformities will be bred out of the line by the fourth or fifth generation.

              Inbreeding is a commonly practiced, essential tool in the pet hobby. When you see the rows of tanks of Sunset platys at
              your LFS, for example, that are all healthy and nearly identical in appearance, this is due to careful inbreeding over many
              generations. The fish are fully healthy, but do possess a relatively homogenous genetic makeup. This can be a problem in
              some instances, such as with a wide resistance to disease, but they are not unhealthy because of inbreeding.

              If you were looking to develop a line of fish with debilitating deformations, you would use those fish as breeders. (Balloon
              mollies, anyone?) Fish with deformations or sometimes dramatic changes in appearance (such as albinism) occur routinely
              in the wild, but simply do not survive as they often present as a target to predators. So the appearance of those negative
              traits is not a response to the inbreeding “causing” a negative trait , it is simply the normal expression of traits the
              fish carries, that it will eventually express, as a line loses its variability and becomes more homogenous.

              Inbreeding allows you to spot and remove the fish with these unwanted traits most quickly from a population. One problem
              with inbreeding however, is that without careful observation and choosing healthy breeders, the line can deteriorate, as anyone
              who has ever put a great line of guppies into a tank to community breed. Within 2-3 generations they will revert toward reduced
              coloring and smaller size.

              In most cases, quality consistency, and appearance of developed traits needs to be maintained through careful selection of
              healthy breeders that will carry on the line.

              Choosing appropriate breeders comes with close observation to select for the largest, healthiest fish, that show a characteristic
              you want to focus on. You would not choose a male guppy to be a breeder with poor body shape or a weak overall physical
              character, entirely because the tail is a particularly attractive color you had never seen before. You could actually do
              harm to the line with no guarantee that the color you desire will even appear. With that situation, I would take the next best
              males from the same brood, and breed the best of those to his best sisters. Then raise up their young, looking for that color
              I wanted, with the conformation and health that the original male did not have. If a new male does show up that carries the minimum
              characteristic you want to develop- then cross that male with his best sisters to work to get a line started.

              One trick used by guppy breeders, where the males possess all the color, and the females do not, is to feed color foods
              to the females before choosing them as breeders, to see the pallette and strength of the colors that the female carries.
              There are foods today that are not hormone based, that harmlessly increase the color of the fish for the short-term (1-2 days)
               and can be of value when making breeding choices. This can be much appreciated when the colors contained by the female
               are important, but cannot be seen. The female Odessa barbs are similar to female guppies, where this can be a big help.

               Choosing Breeders

               Breeding to develop a specific line requires discipline not to become sidetracked by each new minor mutation,
               as every differently colored or lushly finned fish is not necessarily a healthy fish, and will require many additional tanks if you
               choose to pursue it. To see a mutation in a single fish is a careful process and a fair amount of time ( a couple years) until
               you receive a batch of young carrying that trait. That is why I find breeding so enjoyable- you get to form an idea, and then get
               to see what the fish does with those choices that you make.

               I choose breeders for traits I am looking for, aware that getting something may requires a compromise of something else.
               The biggest fish may not have the best color. The fish with the longest fins may not be the largest fish. Etc. By having three or
               four pairs or trios going at a time you can, over time, gradually nudge the line toward the proper collection of traits you are looking
               for, maintaining their overall size, health and vigor of the best fish in the line.

               With many of the Poeciliad livebearers, the largest males will be those that sex out last, and using those males is essential
               to develop or maintain a large size on your fish. However, you may need to breed them before they have fully colored out,
               or the sword isn't fully mature, because to wait too long could limit the amount of reproductive time you will have with that fish.

               I believe that hobbyists have begun to better understand inbreeding today, though there are many that very reasonably
               argue the benefits and essential place that outcrossing plays in many breeding programs. This becomes more important
               when dealing with other animals, such as breeding programs in zoos.

               It comes down to what you are looking for, and the species you are working with, (Discus breeders I’ve known can be
               truly obsessed with the latest wild fish they’d paid to have caught and shipped to outcross with) but I have come
               to believe that inbreeding (brother to sister and parents to offspring) by itself does not harm the fish, when breeders
               are chosen appropriately. When an outcrossing to a wild fish occurs, the next generation breeders must be chosen
               carefully, as you are introducing any number of characteristics that may need to be gradually bred out of the line over
               many upcoming generations, to return the line to stability. Running numerous pairs and trios in this situation
               works best to choose the best individuals.

               The Selective Breeding Process

               Work to keep things simple. Tanks only require a strong and consistant air stream to a large box corner filter
               with charcoal and floss, a splash of gravel for nitrifying bacteria area, kept reasonably clean. Live floating plants
               with a heater with low to moderate light works best.

               I have found that fry do best at slightly higher temperatures than the adults to stimulate feeding and growth for tropical
               temperature fish. (78-80 degrees seems to work best for livebearer/cichlid/catfish fry. With colder water fish, such
               as the Goodeids, the fry temp should stay around 73-74 degrees)

               You want to provide the pH and hardness where the fish will breed comfortably, and it is always best to breed fish that
               are already suited to your tapwater. Bringing your pH or hardness up or down can be done for the time of the breeding process,
               but successful spawning and raising of the young can be difficult or inconsistent. But it is certainly possible using crushed
               coral or oyster shell (to bring up pH or hardness), or Oak leaves, alder cones or muriatic acid to bring down the Ph.

               Tanks are best with a simple, organized setup and consistent approach, appropriate tank space, while keeping only fish
               together that you want together without overcrowding. As a breeder, your focus is on saving and raising the fry. Air and
               temperature, moderate light, covers to prevent adults from jumping out, and quality foods will meet any needs.
               Include a few fine-leaved plants for security and to help water quality.

               The Guppies taught me much I needed to know, but the reality was that I left my total devotion to Guppies after
               about 5 years. Much of their care involved compensating for immunity problems from many generations of being
               maintained in pristine conditions, to produce fish with huge fins that had compromised circulation. I came to believe
               that this resulted in their being prone to minor fin infections, leading to more pristine care, and the fish's immune
               systems continuing to decline over time.

               The immunity issues I perceived could have been due to my husbandry, the strains I worked with, or inherent immunity
               weaknesses, though disease was never a problem for me in my tanks- the problems arose when the fish left
              my setup. Too often, I’d give fish to friends, they’d take them home and the fish then died almost immediately. Today,
              roughly 25 years later, the strains have improved, and there are a number of lines bred by the IFGA, in Moscow, China
              and in Israel that are much hardier and disease-resistant.

              Depending on the species being worked with, and what is being done, breeders will separate their fish based on brood,
              or based on age. When compared to one another, it is something like comparing an Xacto knife and an axe - keeping your
              broods separate and tied to specific parents gives you much greater control over your quality, and allows you to
              breed more exactly. But it can also require more tanks, and when compared to the quality of the fish produced that are
              sorted by age (as I do), it is possible to achieve the same results through larger numbers. The larger the numbers that
              you produce, the greater the potential to produce fish that carry the traits you are looking for.


              Unfortunately, there are a few obstacles to consider, and most are overcome through repeated or multiple efforts,
              patience and persistence. Here is a rundown of what I try to be sure to overcome for a successful breeding program to

              1. Equipment setup. If you are occasionally running into problems with the electricity going out, big temperature
              fluctuations, tanks that leak, filters or heaters that are not dependable, etc., then get those resolved first. I will use
              only new heaters with an important breeding project. Use covered, moderately lit, bare bottom tanks that stay at an
              appropriate, consistent temperature, and simple floating plants (Java moss, Java fern, Najas grass, riccia, water
              sprite etc.) to keep things simple, stable and consistent. I will often sprinkle a little gravel over 1/3 to 1/2 of the
              bottom of the tank to provide nitrifying bacteria and aid filtration. The focus must stay on the fish.

              2. Get good initial stock, and be sure you can keep them healthy before expecting them to breed for you. Poor
              stock may not look as you prefer, and may not breed consistently, or may even throw junk until you get the line
              stabilized and predictable. That can take a lot of time- months- however, when getting well bred, genetically stable
              fish from a reputable breeder in the first place avoids those issues.

              3. After the fish you receive are drip acclimated and settled in, their young- the ones actually born in your water,
              are the all important fish to focus on. Because it is the first generation in your water, there may be some losses, and how
              healthy and prolific they are will eventually be depends on how well they are raised in your new environment. More will
              survive, reach their potential and breed readily with each successive generation as they acclimate to your conditions.
              Until the line is stable- 2-3 generations, the numbers of young that survive will improve, and the fish's colors, markings
              and overall size will increase with each successive generation.

              4. You cannot create a trait. These animals come with many hundreds of characteristics that are no longer expressed,
              but when a species is bred out in large enough numbers, or two individuals are crossed with certain genetic mixes,
              these long dormant traits will sometimes appear, and we will refer to them as a mutation when we see them appear in
              our fish.

              Most are detrimental to the fish, which is one reason why they are not expressed more frequently, and when they
              occur in the wild, the fish will rarely survive long with it (such as albinism). But if the species does not contain the potential
              for a trait in its genome, a spontaneous mutation of something never seen before will sometimes, but rarely, occur. It is not
              possible for you to breed for it, beyond creating a lot of individuals, and hoping that an individual shows the trait you are
              looking for, with the strong possibility that it may never be expressed.

              The traits you work with and develop will come to you - you can't set out, say, to develop a high fin Odessa
              barb, unless you have an Odessa barb appear that carries that mutation, or a closely related species has it that can be
              crossed with the Odessas.

              I have bred tens of thousands of my selectively bred Odessa barbs over the past 13 years, and have yet to see either an
              albino or a high fin fish. The trait has to occur on its own, I can't set out to create it. Other closely related species, such as
              the Rosy Barb, are bred with high fins, and albinos are also in the pet trade, but the mating of high fin Rosie barbs with the
              Odessas, something tried here on more than one occasion, has not produced viable fry. So it is your job as the breeder to
              keep a close eye on each fry that you produce, and identify those that show something that might be of interest..

              Predicting and Planning Egg Scatterer Output

              Predicting the output of a species can be tricky. Assume we are talking about a small egg layer- a barb, rasbora,
              danio etc. How many young reach adulthood will be very different than with Cichlids, for example, where the parents guard
              the eggs and young, and where numbers may be lower. Most livebearers with produce set broods sizes of 10-40 young that
              are fairly well developed when first born. With egg layers that do not guard their eggs, many more eggs are produced.
              Many barbs may release 200-300 eggs with each spawn. However, the number of fry that will reach 1 month old can vary widely,
              for many reasons.

              So you condition them, and the fully mature females are full of eggs and ready to go, the males have been kept separated
              and are also ready to go. You put them together under all of the correct conditions and they eagerly spawn.

              So you have spawned 3 females, and all dropped their eggs. However, you will never grow out 900 fish. Your actual number
              of fry reaching 1 month old, if you do everything right, in my experience, will be closer to 150. If you set out with the assumption
              that 2 pair of fish that can each lay 300 eggs every 2 weeks is going to produce 1200 fish a month for you, you would be very

              Here is why, starting from when they first spawn:

              1. Not all females will spawn. With the Odessa Barbs, I generally put in six females and three or four males, and often
              two or three of them will not spawn. As well, only about 30%-50% of the eggs laid will be fertilized, the rest fungus up,
              and can look like snow over the bottom of the aquarium. But amazingly, enough will have been fertilized to produce 300 - 500 fry.

              2. Parents will eat some of the eggs. In the process of releasing eggs over a divider during spawning, some will still be eaten.
              The depth of the placemen of the divider needs to be roughly 1.5 inches from the bottom, with water over the divider deep enough to
              allow the fish to swim freely and comfortably to chase and dart about. They also need to be able to get to food easily, so that it
              does not simply fall through the screening when they are fed.

              3. Negative Water quality spikes happen, and can often reduce the number of fry. Avoiding your water clouding up by keeping
              on top of water changes following feedings, or when cloudiness is seen, will keep down losses due to water quality problems.

              Important Issues:

              1. Air bladder development starts at birth, and many egg layers need to be raised in shallow water. The water depth
              is kept to 6 inches or below for the first 10-14 days, and the divider is placed in the tank so that there is about 1.5 inches distance
              for the eggs to fall to the bottom. I generally bring the fry to full water depth by 30 days.

              2. The period following their hatching does not need to be an uncertain time of losses until they begin to eat regularly.
              They will begin hatching in 24 hours , and frequent feedings, clean water, and appropriate, gentle aeration are all you really need.
              The filtration should be low or entirely the result of massive daily seasoned water changes.

              With livebearers, and plecos (I do 20-50% daily water changes for new fry for the first week or two with smaller 10-29 gallon fry
              rearing tanks) done so that few new fry are drained away, by siphoning water from the tank through a net breeder. Once the smallest
              fry are ready for brine shrimp, growth will go quickly, and they can be moved into larger tanks at 14- 30 days, depending on the
              size of the fry. Odessa barb fry are fed 3x per day, at 8am, 3 pm and 9 pm, with each feeding followed by a 50% water
              change. Odessas are generally not moved to their own tanks until they are 30 days old.

              3. Micro-foods such as vinegar meals, microworms and Paramecium are used for the egg layers, depending on the species,
              and Baby Brine Shrimp is always in production and kept frozen in ice cube trays for use on a moments notice.

              4. Some will be born with issues that keep them from thriving. At first I was breeding barbs in a tank that was too
              deep, and easily 50% of my first spawns developed swim bladder problems. They were unable to stay off the bottom, and
              spent their days struggling to swim up, using their energy that should have gone into growth. The majority were cured by raising
              them in hanging net breeders where they stayed within 2-3 inches of the water surface, removing them one by one as their swim
              bladders developed properly. This took about 2 months, and resulted in undersized fish, with some that never recovered.

              Each species that you work with, be they egg layers or livebearers, will each have its own tricks and idiosyncrasies.
              Raising cichlid fry is different than raising egg scatterer fry, which is different than raising killifish or rainbow fry, and
              each of those are entirely different from harvesting livebearer fry. Most will require their own types of tank set ups,
              net breeders, tumblers or whatever-

              5. You may be doing everything correctly, but with some species in a normal location where they are exposed to
              daily light cycles and seasonal temperature changes, they may naturally stop breeding from about October to April
              (depending on species), and there will be no young, or very reduced spawns. This is the case with most of the species
              at Select Aquatics, due to one wall being entirely windows. The seasonality of the fish is different for many fish, and is
              dependent upon where in the world they initially come from. But the catfishes breed from November through
              January, many of the Goodeids breed from December to April, and some of the other Poeciliads will breed from
              early April to mid June. Though difficult for planning sales, fish breeding during their normal breeding seasons is
              healthier for the fish, leading to healthier batches and longer lifespans.

              You can breed and produce a lot of fish, but it will happen as a result of your mastery of making it happen, not
              the mathematics of what you assume is possible based on their reproduction rates. You can make money at this, and
              produce a lot of great fish, but like everything else, it doesn’t just happen, at least not at first. The obvious
              advantage of greater numbers are the mutations that could occur, and careful choice of breeders
              becomes far more interesting when there are a far greater number of fish to choose from.

              Choosing individual breeders can be challenging. With fast moving, schooling fish such as the Odessa barbs, it can
              be difficult to pull out a specific fish, particularly when they will “wash out” when stressed, which is exactly what you trigger
              when walking to the tank carrying a net. But there is a way to do it.

              Remove any box filters from the tank, and the majority, but not all, of the plants in the bare bottom tank. Leaving
              some plants encourages them to hold on to their color. I then leave the tank alone for a few minutes to let them settle

              Then I take a 15 inch black fine mesh net and slowly enter it into the aquarium so that it descends behind them as they
              group toward the back of the aquarium. Then I bring the net forward slowly to scoop up as many of them into the net
              as possible. Then I lift up the net and place the edges against the rim of the aquarium, so that it hangs down into the water.

              Then, with a small net, I will slowly reach in and carefully remove the best looking fish to be used as breeders. If there
              are too many fish in the net, I will gradually remove the inferior fish first, and release them into the tank to free up space in
              the net. If I am looking for four males, I will choose six, putting them into a separate container where they can sit
              quietly. After setting the tank back up, I will then remove the two weakest colored males of the six that I had pulled.
              And then use the top 4.

              Having a batch fail for any number of reasons will happen occasionally, and you must realize that the fish spawn naturally,
              and are releasing eggs on a regular basis. So when a batch fails, try to determine the reason, learn from it, and then get
              the tank cleaned up and reset up for the next effort, without making the same mistake the next time around. I once restarted
              spawning with the Odessas when batches failed 4 times in a row. It was from that experience that I learned not to use females
              older than three years old for breeding, and similar failures have not occurred since. But that is how you learn- sure, you will
              get that sick feeling in the pit of your stomach when a batch fails, but you can only make value of that lost effort by starting over
              again and learning from what went wrong the previous effort.

              Mutations and Some Basic Genetics

             I have been asked why I seem to get so many mutations, such as albinos and leucistic fish -white individuals with black eyes-
             among so many of my fish.

             My getting the incidence of mutations is simply the result of observing every young fry closely, then separating the
             anomalous individuals from the others. They are then bred with one another, or if only a single individual, I will breed that fish
             with a normal colored sibling. Some of you may remember the Punnet square from High School biology days, which more
             clearly expresses what I am about to describe. This basic initial introduction to trait genetics is all that I have needed to be
             familiar with. However, you can certainly explore this subject further- into sex linked characteristics, for example, with a decent
             text on basic genetics.

             The first spawns (The F1s) of the fish with the mutation, when mated with a normal appearing sibling, will be all normal
             colored, but the mating of two of those fish will produce spawns where 25% may produce fry that show the recessive
             trait/ mutation of one of their their parents. (This would be the second, or F2 generation). They will hopefully produce enough that
             show the trait to breed them with one another, starting a new line, where 100% may eventually show the recessive trait.

             The fish showing the recessive trait, when bred to one another, will produce all young carrying the trait- albino to albino will often
             produce all albino young (but not always). 50% of that F2 generation- the other siblings, however, though normal colored, will be
             heterozygous (“Het”) for the recessive trait, and those, when mated with one another will produce up to 25% young
             that may show the recessive trait.

             The remaining 25% of the F2 generation will be pure dominant, not carrying the recessive mutation at all. So 75% of the
             2nd generation spawn (the F2) is normal in appearance, and up to 25% may show the recessive trait. Of the 75% normal
             in appearance, 25% are pure dominant (they do not carry mutation) and 50% carry the recessive trait, but do not show it.
             They will all look dominant, however, and it is not possible to determine which carry the recessive trait, and which do not,
             until you breed them with one another.

             Generally, any new mutation will be weaker, undersized and possibly even born with swim bladder problems.
             Some may simply choose to treat these individuals with the special “aquatic hydrovortex transition tool”
             (flush them), but something different can be interesting, attractive and desired by other hobbyists, and the trait may never
             be developed without breeding out those individuals. These fish occur as natural mutations, and must be grown out
             to become as healthy as possible before being used to start a new line.

             The high fin mayae were at first very undersized and weak, but through generations of choosing the largest, healthiest
             individuals, and crossing back, their size and constitution after about 4 years and 5 generations
             began to approach the size and vigor of the normal fish that do not carry the mutation.

             With the “nezzy” (Xiphophorus Nezahualcoyotl) swordtails, from a batch of roughly 30 young I would get three or
             four whose growth would take off, both males and females, and they would grow into large, husky, healthy fish.
             I selected for those individuals. Their color and finnage might not have been the best but their size and health needed
             to be established at first. Then there would be a couple fish with great color and finnage, healthy in all other
             respects, but not as large, and they got set aside to later cross with the largest individuals. Then, as with most
             swordtails, there will be 3 or 4 “early-maturing” males in a drop that sex out early and are undersized. This is an evolutionary
             development that allows for some individuals to pass on their genes early. Those must be removed from your breeding
             stock. When the sword develops, the overall body growth stops and sexual maturity will begin their spawning.

             The best males are those that sex out late, looking similar to females until secondary sexual characteristics
             (The gonopodium and sword) develop . One fishkeeper that should know better swears that some swordtails are born
             females and change to males later in life, which will never happen. No swordtails or mollies change sex and are
             then fertile. Hobbyists are simply seeing later developing males. the production of testosterone can occur as females
             age, causing older females to show male characteristics, but those older fish are never fertile as males or females.

             I’d then set aside the remainder of the spawns as a “reserve” if anything were to happen to the breeders. Rarely, there
             will be fish in that reserve that will grow into big, nice looking fish, outpacing those I had originally chosen. When picking
             breeders, I select for a blocky, muscular shape and big finnage. As I mentioned before, the interesting challenge
             was choosing and putting together the best breeders after their promise was clear, but before they had gotten too old.

             The swordtails are said to possess 3 basic genetic paths, producing large robust fish, midsized fish, and early maturing
             males. My efforts are generally to focus on developing a line that is primarily the largest, latest maturing individuals.

             Myths, Non-myths and Truly Odd Beliefs

             If you are to carry your head high as a breeder who claims to know what you’re doing, you need to be aware of the
             issues where expressing your opinion may get you into trouble. The trick is to hold on to your opinions where everyone
             will still get along with you, and let you see their setups. The problem with the theories below is that both sides often have
             a point, and it is easy to see why the conflicts continue. Only your own experience will determine which side of the argument
             you end up on.

             Theory #1- Immunity Compromise

             Addressed earlier, selective breeding with a developed line that has been dramatically developed over a long period of time,
             taken beyond its wild form in finnage and color, you may notice that the fish are prone to fin rot and other bacterial
             infections. They may be less prolific, or produce a greater percentage of unhealthy young when kept as you would other,
             non-line bred fish of the same species.

             Guppy breeders I have spoken with are generally convinced that immunity stays intact in the line-breeding programs
             they use, and that tying any inherent weaknesses of their fish’s immune system to line inbreeding and good clean living
             is nonsense. They believe that like ourselves, the fish are exposed to pathogens they fight off routinely, regardless of    
             water quality, and the infrequent fin rot occurrences can be controlled with the use of salt in the water, careful attention
             to cleanliness, quarantine of outbreaks and choosing breeders that are healthy and strong. In fact, they may even believe
             that simply culling any fish that become sick strengthens the immune system of your line by preserving the healthiest fish.
             They claim the fish are perfectly healthy, thank you very much. The long finnage has obvious circulation issues, and a carefully
             bred fish with proportionate size and musculature should have no problems with disease outbreaks.

             The other side concludes that a long multigenerational history of being raised in exceptionally clean, bare bottomed tanks,
             selectively bred for finnage and color, produces fish that lose their ability to fight off infection. The fish never face genuine
             challenges to their immune system, and over many years of this husbandry, it is no surprise that a sincere challenge to their
             immune system results in quick deaths. Some guppy breeders even claim they “don’t have any diseases in their fishroom”
             further compromising their argument that fish are exposed to all diseases all the time as a normal condition of aquarium water.

             My experience tends to support the latter belief, but I have seen lines of Guppies in the last couple years that
             are much improved, and will grow out luxurious full delta tails, even when kept in planted, gravel bottom tanks.
             Those I have seen most frequently have been from European or Russian stock, but it does indicate that the issue
             is being addressed effectively, as can be seen in some of the quality lines that are now available.

             Is it necessary to outcross a carefully line bred fish, or possibly face the eventual destruction/ collapse of
             the line? I have been told that an outcross should occur by no later than the 11th generation, and generally by
             the 6th. Many breeders will separate a newly acquired stock into two lines, line breed them separately, then
             cross them with one another every 5th or 6th generation, as sort of a compromise between the two schools of thought.
             The genetic diversity is slight, but many feel that following that practice is the best way to maintain the strongest

             There are those that claim that outcossing to address concerns for immune system strength are uneccessary, and that a
             carefully bred line will stay perfectly healthy without outcrossing (such as the fish produced by the Xiphophorus stock center
             mentioned earlier). In fact, outcrossing is a risk that introduces unwanted traits, flaws etc. into a line that has been carefully
             developed to remove much of what you are re-introducing.

             This is often what happens when a breeder decides to cross a highly developed fancy line with a wild form to
             “strengthen the line". You will find that this is one of those topics that tends to bring out the color and finnage of the
             fishkeepers. :)

             My experience has been that “hybrid vigor” is certainly a real thing, and outcrossing an established line to something
             else will produce fish that are often more robust. But a careful program of line breeding should be able to maintain
             and continuously improve a line when done properly, without the need to outcross. The Xiphophorus stock center, with
             their line bred fish that go back over a hundred generations would seem to prove that strict line breeding can be done
             properly. Keeping two lines of a strain is certainly a good means to outcross, and I imagine that some hybrid vigor should
             result if the two lines had been allowed to develop independently for a long enough period of time.

             Theory #2- Growth Hormone Inhibitors

             The first side of this theory holds that the largest “alpha” males in a tank of single species fish secrete a substance that
             functions as a growth inhibitor against other, younger developing males, ensuring the physical dominance of the largest male.
             This becomes a very important bit of information with male grow-out tanks. Because of this, selecting for the largest
             males for breeding is skewed toward one or two individuals that had experienced a growth spurt at a young age, and then
             may have suppressed the growth of their siblings. Choosing for other traits such as color and finnage then becomes even
             more difficult. Frequent water changes to dilute this chemical must be done, as well as possibly separating out the promising
             younger, but smaller males to other tanks so that they can grow out to their potential.

             The other side holds that there is no such thing- after all, such a substance has never been isolated and identified-
             and that normal random growth advantages provide quicker access to food and bullying of younger fish, creating the
             growth advantage.

             It is accepted by most fishkeepers that something exists that has a clear affect on the fish, in a manner that a
             growth inhibiter would exhibit. However, when you are trying to raise up young Xiph. Swords, a fish that can get
             fairly large with the right feeding and water quality, It would certainly be nice to know if such a substance exists,
             and Identifying that substance would certainly answer a lot of questions fishkeepers have wondered about, but its
             existence has yet to be proven. Like other breeders, the assumption of its existence works well when developing large
             fish, so I'll play along, because assuming that it exists does work. Heavy water changes and raising the largest males away
             from the others does produce the greatest percentage of larger fish.

             Some also believe that young males may stunt their own growth in response to visual cues received from larger males in
             their territory. Others insist that only a relatively small percentage of males are ever meant to be exceptionally large fish, and
             though we can develop a line of predominantly large morph fish, the presence of a range of smaller males is always to be

             Theory #3- That Swordtails will Change Sex

             No livebearer commonly said to possess this ability will ever change from a sexually mature male or female into a
             fertile, sexually mature member of the opposite sex. Most species of fish mature at reasonably set rates that can be
             predicted without problem when taking temperature, feeding, and light cycles into consideration. So when a fish does
             not fall within those rough parameters, we assume it is a very special circumstance. With the poecilia velifera, for example,
             I have had young males take up to a year to show a gonopodium, but that fish had always been a male, it just just took an
             exceptionally long time to sex out.

             Theory #4- Community Breeding to Maintain the Wild Form

            This holds that opposite the intent of selective breeding, a line allowed to breed randomly in a single species tank
            will strengthen natural, wild characteristics, ensuring that the fish will become as close as possible to their original,
            wild form. Sort of a selective breeding by “natural” means. This is often cited by those breeding rare or wild type fish
            who personally hope to divert the fish from its wild type as little as possible, thinking this approach will yield the
            closest to the continued appearance of the wild population.

            The other side holds that an aquarium is an inherently artificial environment, and that every effort to selectively breed
            the healthiest, strongest individuals should be done, as these are the fish most likely to survive in the wild, and breed
            naturally, and are best suited to continue the line. When allowed to breed indiscriminately, the artificial confines and
            lack of predators picking off the weakest fish in the aquarium encourages unhealthy fish to incorporate themselves into
            the population, while self selecting for traits that provide an advantage within the aquarium, but not necessarily in the wild
            (such as smaller size). In my opinion, some will hold onto the flawed assumption that we know how to develop a fish
            that best represents its wild form, as a result of choices that we make for the fish in our home aquariums.

            My experience is that many fishkeepers holding the opinion that the wild form can be maintained by leaving them
            alone rarely provide an environment that addresses many aquarium inherent modifiers. Keeping a larger, single species
            tank that populates randomly is not difficult, particularly when your concerns are providing enough plant cover to keep the
            young from being eaten, and simply producing healthy fish.

            A genuine effort to replicate a wild situation would require at least a hundred gallon tank for a species that reaches an inch,
            and then there would need to be the occasional introduction of predators, cyclical live food, day/night temperature swings
            and seasonal light and temperature variations to begin to head you in the right direction. We can only do our best to raise
            healthy fish, but we can’t claim that the fish we keep are exactly as they would be in the wild.

            Theory #5- Sell them so they Die!

            This thinking is that when you have to go to great lengths to carefully, selectively develop a line of nice looking fish,
            and you are ready to sell those fish to someone else, it becomes the responsibility of the customer to keep them as they
            need to be kept, and telling them the lengths they may need to go to provide a proper environment will only discourage the
            sale. So it’s best to keep quiet. Some breeders feel that what the customer needs to know will be the result of their research,
            not your providing the information. If they die (as they often will), they’ll have to come back to you for more fish anyway.
            Essentially, if they leave your care and they look great and are in all other aspects perfectly healthy fish, the fact that someone
            else may not meet their needs is not, as the breeder making those fish available to them, your problem. One wholesaler once
            shared the advice that "once a fish leaves my doorstep it is no longer my responsibility."

            On this I could not disagree more. The same applies to breeders that feed color hormones to their fish before being
            sold so they look better, not especially concerned that the fish could be made sterile in the process, rationalizing
            that the customer probably won’t breed them anyway. As a breeder you have a responsibility to provide fish that meet
            the customer’s reasonable expectations in as many ways as possible. Some people can’t keep certain fish, due to their
            water qualities or inexperience, granted. But I strongly believe that it is up to the breeder to provide any and all information
            the customer needs to keep them going, just as I would expect when I am on the other side of the fence. I keep what I do
            today in large part because of the information those first guppy breeders gave me. Those original fish are long gone,
            but the information has stayed with me, allowing me to continue keeping them today.

            Actually doing it. What steps are best right away?

             Besides time, selective breeding requires space. the only way to increase your odds for beneficial mutations is through
             breeding larger numbers. Only through breeding a fish out by the many hundreds will you increase your odds enough to
             create genuine, spontaneous mutations. When first keeping Xiph. mayae, I was in the process of making the line consistent
             (breeding out the tendency toward early developing males, for example), and was breeding them out 3-400 at a time in 40
             gallon breeder tanks. And eventually, I did get my first albino after about 3 years.

             I have had other hobbyists tell me that an albino cannot be created spontaneously, that a previous cross with an albino
             fish had to have occurred. This is not true. Some species are more prone to produce albinos than others, but in my
             experience, many, if not most, species have the potential to produce occasional, spontaneous albinos. The health and color
             of the fish produced can vary widely, and some may be too weak to survive.

             Recently I obtained a single pair of longfin plecos with a greenish tinge to them. The line had been badly hybridized, and though
             there were many spectacular young being produced, many of the first batches were a hodge-podge of various lines- albinos,
             calicos, short fins and chocolates. The line needed to be made consistent, and the quality of that consistency needed to
             represent the best the line had to offer- excellent finnage and the best green color that I could tease from the line. The line
             has now been in production for 12 years, and until recently, 23 tanks of 29 to 55 gallons were devoted to just the
             Longfin Green Dragons. Of all of those fish, roughly 170 top quality Green Dragons were produced each year, of
             thousands grown out. The remainder were short fins, albinos and fish of poor color or finnage. The percentage of quality
             longfin Green Dragons increases with each generation, and though they have been going for 12 years, they are only in
             roughly their ninth generation, and are still a ways from becoming genetically stable, or breeding consistently.

             So, what is “Selective Breeding?"

            1. You start out with a pair of fish in a small bare-bottom, filtered tank with a few fine leaved plants. (The tank being
            small so that you can always see them easily, and they are able to find food easily as they adapt to their new home),
            and at least 3 other tanks to be used for that particular line of fish. The size of the tanks must be comfortable in size
            for the species you choose to work with. I have livebearers such as guppies and swordtails in mind as I describe this
            process, but the overall process for any species of fish would be similar. Egg scatterers or egg layers providing large
            numbers of fry will need special accommodations, but this set up can also work for many egg layers such as killifish,
            rainbows, etc..

            To provide security for young, this first tank should contain a moderate amount of plants that fry can easily hide in.
            (Java moss, Java fern, subwassertang, najas grass, riccia and water sprite are some of the best.) The male, when the
            female becomes gravid, is moved to a second tank, leaving the “home” tank to the female. This way she can have her
            young without the added stress of being moved.

            2. For each line of fish you will need a minimum of 4 tanks. One for the breeder pair, trio or pairs,
            one for unsexed new fry, one for males grow-out and one for females grow-out. This assumes that you will cull all of
            the fish that don’t qualify as breeders, bringing your entire stock of that line down to the few breeding pairs with each
            generation. Keeping your culls, at least for a while, is best, for occasionally a fish that had been passed over as a
            breeder matures out into a huge fish, or one you may want to breed after all. If you have a loss of your breeders, it is
            also nice to know that you have fish in reserve. But 4 tanks gets the process started.

            3.When the young are born, remove the female right after she drops, and either allow her to recover for 3-4 days in
            another tank, or return her to the adult tank. Leave in a sprig or two of Java fern or moss for the new fry to hide in, and to
            help maintain water quality while also being a source of infusoria to pick on. That now becomes the fry tank. Feed baby
            brine shrimp lightly 2x a day to the new fry. With many egg layers, the young will need to be raised up however necessary,
            in a fry tank to then be separated by sex as they grow out.

            If the fry tank is 5 gallons or smaller, change 50% of the water daily with clean, seasoned water from another aquarium.
            Do heavy water changes for their first 2 weeks. If possible, using aged water from the tank where they were first born is
            ideal, then add dechlorinated tap water to the parent tank. Around three weeks, guppies can be sexed, while other species can
            be watched closely for the first signs of sexing out. More information on breeding's egg scatterers can be seen in the YouTube video
            "Breeding Odessa Barbs, Vids 1, 2 ,3."

            Move the sexed females first to their own tank, this will ensure that few of your females will have been fertilized. For livebearers
            where the mature males possess a gonopodium, separate sexes as soon as the gonopodium development is seen, or
            a darker “gravid spot” begins to appear on the females behind the “belly” area. Once a working gonopodium is in place,
            the males can mate, regardless of whether other secondary sex characteristics have occurred (such as the development
            of a sword). Raise male and female groups separately to sexual maturity. By separating the sexes you are not only
            preventing unwanted breeding, but you are also substantially increasing the growth and size of the fish, as they are not
            expending energy chasing one another to compete while trying to breed.

            4. Raise them up to determine which will be early maturing males, undersized, or otherwise unhealthy fish, and remove
            those individuals. Move bigger, later maturing males and all fish that may become breeders to a tank of their own to provide
            more space and better water conditions, or if maintaining just 4-tanks, cull inferior fish. Continue the process with the females
            as well, choosing for size, color confirmation, etc. Save the culls if possible (in case something happens to the better ones).
            It will be at this point that you will need to make decisions such as: should I choose one fish that is larger and more robust, whose
            color isn’t so great, or should I choose this other fish, whose color is spectacular, but is undersized? If you have the
            spare tanks, you would do both, and then possibly cross the best young that each mating produces. Without the extra tanks, the
            decision is yours, but overall size takes a long time to reclaim when lost. The basic rule, when selecting for traits, is to first select
            for overall size, then finnage, then color.

            5.Raise them up to when size, color, and finnage are set enough to compare one against another, and choose the best fish.
            With guppies this is at about 3.5-4 months, with swords it can be substantially longer- 6, 7 months. These are your breeders.
            Generally, a rule of thumb is that of a batch of 30 babies, you will get 1-2 pair that will be breeders.

            6.Continue the process until your breeder pairs are producing young that consistently carry the trait you are looking for.
            I have been told that it takes 11 generations to fix a trait, so that it becomes as consistent as it is going to get- where
            ideally every young in the brood expresses the trait. With guppies a generation is 4 months, with helleri swordtails and
            platies, a generation is 8 months, with angelfish and most cichlids it is closer to 10 months. My experience has been that
            I start to see acceptable consistency (70-80% of young carrying the trait) by the 6th generation.

            7. It is possible to have your selective breeding program "Crash" on you. Say you are breeding for long finnage on a pretty fish.
            You are faced with a tank of young sexed adolescents that are a combination of fish at various sizes and health, color quality, and
            finnage length. Over time you will get a feel for making the best choices where the traits you want will likely show up in the young
            that your choice of breeders produce. One basic rule that I follow is that with these longfinned, pretty fish being used as an example,
            I will first develop a robust longfin fish first, without specific concern for the color. Then, when I have a decent sized group of
            consistently robust longfin fish, I will then select breeders with the best color. (Remember: Size, then finnage, then color.).

            If I try to move too quickly, making changes in both the finnage and color, selecting for more than one or two traits at a time, without
            the proper attention to their size and overall health, you could produce fry that are a worthless mishmash, and that don't
            produce the traits you are looking for. So when you are selectively breeding, the pace of introducing traits, and how you go about
            establishing them, is where experience and skill come into play. Moving too quickly can cause your line to crash.


            Do things right the first time, and don't compromise or take short cuts. Change the filter floss every couple weeks, and everything
            else comes down to regular water changes, types of food fed in small amounts as often as possible, proper temperature,
            aeration, critical observation and patience. I also read constantly from every book and magazine I can find on any and
            all of the fish that I am working with.

            You must feed newly hatched brine shrimp to the fry and a good dry food daily, possibly with beefheart or chicken liver
            mix a couple times a week. I also use the “Golden Pearls”, produced by Brine Shrimp Direct, and often feed smaller new fry
            a mix of powdered dry food dissolved in water. I also feed live daphnia and other live foods. The biggest killer of new fry is mulm,
            collected debris, and inconsistent tank or water conditions.

            I find that I'm constantly challenged, and pleased with new and interesting things that seem to happen almost daily. I often wondered
            if focusing on just a couple lines could become boring or a burden, but the secret is to keep it simple and within your time, energy
            and budget. Keep your projects exciting, fresh and challenging. Today I happen to think that the bare bottomed tanks look great- I
            don't miss the gravel and landscaping. The emphasis is now totally on the fish. And what I ended up with is certainly a long way from
            what I had expected, back when I thought I knew what I was doing!

               Greg Sage
               Copyright 2023





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